TemperingTempering AnnealingAnnealing Stress RelievingStress Relieving NormalizingNormalizing QuenchingQuenching

Reheating a Hardened MaterialReheating a Hardened Material –Increases Ductility and Toughness Three ComponentsThree Components –Temperature –Time –Cooling Rate

Heating and holding a suitable temperature followed by an appropriate cooling rate.Heating and holding a suitable temperature followed by an appropriate cooling rate. –Quenching has to occur –Produces desirable changes in the material properties or microstructure

Relieves stresses that remain locked in a structure as a consequence of a manufacturing sequenceRelieves stresses that remain locked in a structure as a consequence of a manufacturing sequence –Welding –Cutting with a torch –Machining

Both Thermal and Microstructure point of viewBoth Thermal and Microstructure point of view –Thermal Heating then cooled in still or slightly agitated airHeating then cooled in still or slightly agitated air

Rapid cooling of steel from an elevated temperatureRapid cooling of steel from an elevated temperature –Typical Quenching techniques WaterWater OilOil AirAir

What is the hardness required?What is the hardness required? –Refer to Heat Treater’s Guide How Deep do You Need the Treatment?How Deep do You Need the Treatment? –Case –Through What type of Heat Treatment is required?What type of Heat Treatment is required? –Tempering, Annealing, Stress-Relief, Normalizing, Quenching

Turn On FurnaceTurn On Furnace Set To Appropriate TemperatureSet To Appropriate Temperature –Determine from references Place Metal In Furnace When Up to TemperaturePlace Metal In Furnace When Up to Temperature –Leave for determined time Remove and Immediately QuenchRemove and Immediately Quench –Quench in appropriate fluid Oil, Water, AirOil, Water, Air Re-Set Furnace Temperature (Tempering)Re-Set Furnace Temperature (Tempering) Place Metal Back in Furnace (Tempering)Place Metal Back in Furnace (Tempering) –Leave for determined time Remove and Cool at Designated Rate (Tempering)Remove and Cool at Designated Rate (Tempering)

Establish the type of steel that will be usedEstablish the type of steel that will be used Determine the desired propertiesDetermine the desired properties –Hardness Case/ThroughCase/Through Choose the proper quenching techniqueChoose the proper quenching technique

Metals Handbook Desk Edition, Second Edition.Metals Handbook Desk Edition, Second Edition. –JR Davis, Davis and Associates, 1998, ASM International Steel Aluminum Stock List and Reference Book,Steel Aluminum Stock List and Reference Book, –Jorgensen Steel, Earle M. Jorgensen Co., (Section S.)